The present invention relates to an apparatus for producing a band having a curve, especially, a curved flat composite cable, the apparatus being comprised of several clamping jaw pairs arranged downstream of a weaving device for withdrawing the individual lines which form the composite cable.
DE 198 16 666 A1 discloses the production of a band as woven composites with a curve in the plane of the weave. In this reference, an apparatus is also disclosed for the production of curved bands. The disclosed apparatus comprises a weft intake location of a narrow materials loom to which a gripper mechanism for clamping the warp threads with two gripping clamps is arranged. A clamping jaw pair, hereinafter referred to as grip clamps, is moveable and its jaws are driven and the other clamping jaw pair is fixed.
In order to weave a curve, the moveable grip clamps are closed to thereby clamp the warp threads, while the fixed grip clamps are opened. Then, the moveable grip clamps are moved about a rotation point, which leads to the result that the warp threads of the woven composite are moved during each cycle by an amount which increases from an angle which is nearer to the rotation point toward an angle of the grip clamps which is further from the rotation point. A curve is produced in the woven composite on the side toward the warp threads which are withdrawn by the relatively shorter amount. At the end of the movement, the fixed grip clamps are closed and the moveable grip clamps are opened and these moveable grip clamps return in a direction in opposition to the withdrawal direction back to their start position.
The course of movement is periodic. A curve is produced whose radius is given by the distance of the rotation point from the warp threads and whose sense of direction or handedness is given by the position to the right or the left of the warp threads relative to the position of the rotation point. To produce straight pieces, the moveable grip clamps are moved in a straight line manner.
The disadvantage of this apparatus is that the withdrawal process proceeds in a start-stop manner, in that, in connection with the movement of the moveable grip clamps back toward their start position, the transport of the warp threads must be abruptly interrupted. Particularly in connection with the working of warp threads of substantial mass, such as insulating electrical lines in comparison to pure textile yarns, strong fluctuations occur in the material which may be propagated up to the line building mechanism in the weaving machine or loom and, in connection with an increasing weft count, the production of a composite without problems or disturbances is increasingly impacted and is even fully impossible. Moreover, the apparatus permits only a very limited variation of the radii of the curves.
The present invention provides a solution to the challenge of providing a substantially uniform movement of the warp threads.
In accordance with the invention, this challenge is met in that all of the clamping jaw pairs are moveable relatively along the withdrawal direction and are driven and are pivoted.
In a preferred embodiment of the present invention, two clamping jaw pairs are arranged which are moveable back and forth along the extent of the withdrawal direction in alternating manner by means of a drive mechanism which engages the ends of the clamping jaws, whereby the amplitude of movement of both sides is independently variable.
The drive mechanism can preferably be comprised of a crank drive system, whereby, on each side of each clamping jaw, a crank drive engages and the stroke of the crank drive of one side relative to the stroke of the crank drive of the other side is adjustably variable.
In a further preferred embodiment of the present invention, a plurality of clamping jaws are arranged on one or more pairs of driven, endlessly circulating, non-rotatable drive means such that the clamping jaws are arranged in opposing manner by pairs. The clamping jaws comprise start cranks with sloping crank or start surfaces. Start rollers are provided adjacent the drive mechanism which are swingable into the path of movement of the start cranks. Elastic return movement elements, especially, spiral springs or flat springs, are preferably arranged between adjacent clamping jaws.
The drive mechanism, which is not extendable, comprises, preferably, roller chains or toothed drive chains. With the deployment of the inventive device, it is possible to use as warp thread differing material in order to meet the most stringent demands of the warp thread customer.
The warp threads are, for example, insulating copper lines, hoses for the conveyance of media and for pneumatic and hydraulic arrangements, armored or reinforced cords or yarns of cord, steel, carbon, or the like, light conducting cables, and similar materials.
The radii of the curves can be adjusted within a wide range which is not dependent upon the width of the clamping jaws. It is possible, for example, in correspondence with the demands of the aircraft and commercial vehicle industries, to finish or produce flat cables.